Final answer:
An unbalanced force scenario occurs when the net force on an object is not zero, resulting in a change in the object's motion. Examples include a car moving at a constant speed with unbalanced driving and resistance forces, and an ice hockey stick pushed from both ends with equal force, which is in equilibrium.
Step-by-step explanation:
When the net force does not equal 0 N on an object, the situation is referred to as unbalanced. This means that the forces acting on the object are not cancelling each other out, which results in a change of the object's velocity - either speeding up, slowing down, or changing direction. The second part of Newton's First Law states that a net force acting on an object is equal to the rate of change of the momentum, indicating an unbalanced force situation.
For example, consider a car that is moving at a constant speed on a flat road. If there is more force being applied by the engine than is being opposed by air resistance and friction, then the net external force is not zero. However, if forces such as air resistance and friction match the engine's thrust exactly, then this will result in a situation where the speed remains constant despite a nonzero net force, illustrating a dynamic equilibrium.
Another example is friction, which is an external force. When an ice hockey stick is lying flat on ice and is pushed from both ends with equal force, the net external force is zero, and the stick is in equilibrium, assuming no other forces act on it.